Generally, stadium chairs are collapsible chairs. In this example, a collapsible chair includes a chair in which the seat portion of the chair changes positions, e.g., based on whether a person is sitting in the chair or has stood up. For example, as a person stands up, the seat portion of the collapsible chair moves in an upward, vertical direction. As a person sits in the collapsible chair, the seat portion moves in downward, vertical direct. The periodic movement of the seat portion of the chair, e.g., as a person stands up and sits down, prevents an individual from placing items (e.g., a purse, a backpack, and so forth) in a secure position on the collapsible chair. For example, as a person stands up from the collapsible chair, the upward, vertical motion of the seat will displace (e.g., knock off) personal items that were previously placed on the seat portion.